Junction box for electric lead-covered cables and the like



' .Jan. ,1, 1929.

- 1,697,539 E. oLssoN El AL I JUNCTION BOX FOR ELECTRIC LEAD COVEREDCABLES AND THE LIKE Original Filed Nov. 11, 1924 E. 0[sson *7 5. El/

Mveu 76R Patented Jan. 1, 1929.

UNITED STATES PATENT OFFICE.

nman OLSSON' AND BERNHARD ELL, or 'snnipnnnne, NEAR srocniromu, SWEDEN.

JUNCTION BOX FOR ELECTRIC LEAD-COVERED CABLES AND THE LIKE.

Original application filed November 11, 1924, Serial No. 749,213, and inSweden December 15, 192%.

Divided and this application filed March 3, 1926. Serial No.. 92,069.

The present invention relates to an improvement in junctionorcoupling-boxes for electric lead covcred cables and the like and,

' more particularly, theinvention refers to an improved tight packing atthe cable inlets.

In the junction-, or coupling-boxes, hitherto known, it has been amatter of great difiiculty place of the j unction-boxl Such a tightening1 is, however, very desirable partly in order to.

prevent the insulation contained in the cable from flowing out andpartly to prevent it from contacting the humidity of the open air. Itisalso necessary, when joining. the leadcovered cable,'to join the cablelead-sheaths carefully with each other and with the box or fitting toobtain a reliable earthing. This earthing is very importantfior thesecurity of service of the electric plant and in many countries it isalso prescribed in the-law.

In the arrangements, hitherto known, of this kind it is ratherimpossible to determine afterwards if the earthing has been carefullycarried out or not. Ifa' misfortune hashap- 2 .pened it is also notpossible to ascertain if it refers to the packing orthe earthing andusually the wholelioxin such a case is destroyed. j x K Thepresentin'vention has for its object to avoid this inconvenience-andconsists in the fact that the'box,4jat the cable inlet. or inlets isprovided with anadjustablesleeveor ring shaped packingconstructed of anelastic material, said packing being entirely (n-"partlycovered with asoft metalin such a way that at the same time thecable or cable end,which passes through thejpacliing, obtains atight 7 adapted to fit overthe cable,

connection with the box, this latterwill be connected with the metalliccable sheath by means of the metal covering the packing The invention isillustrated on the annexed drawing in which Figure 1 shows the packing,while Figure 2 is a section. through apart 'of' a box provided with sucha packing. to'obtain a perfect tightening round the inlet Tlic packingconsists, in the embodiment sh own,o f a rubberring- 1', which at bothends is provided with a lead-capsule 2. The ring is placed roundthe-lead-sheath 8 of the cable (Figure 2) after which it is pressedtogether by means of any suitable device. In the embodiment shown. thecable "is supposed to be inserted in a junction-box 4, provided with ascrewed tube-piece 5, on which is screwed a sleeve-nut 6, which pressesa ring 7 or the like against the packing-ringl, 2 so that this iscompressed, This causes agood tightening In a stuflin g box for electriccables or the like, a ring shaped packing of elastic material aehannelshaped ring of soft metal engaging. each.end of said packing ring,sa idpacking being exposed between said, rings, and means to compress saidrings longitudinally whereby the elastic material between said cups aswell astherings are pressed against said cable and said stufiing box toform a water-tight joint.

' BERNHAR-D ELL.

EINAR OLSSON.

